Book/Report

FZJ-2018-02503

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Theory of the rippling instability in toroidal devices

Rogister, A. (Corresponding author)FZJ*

1985
Kernforschungsanlage Jülich, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/18216

Report No.: Juel-1992

Abstract: The theory of the rippling instability is developed for axisymnetric toroidal plasmas including ion viscosity and parallel electron heat conduction, but assuming that the growth rate is small compared to the wave angular frequency $\omega_{o}$ = (1 + 1.71 $\eta_{e}) \omega^{*}_{e} \cdot \omega^{*}_{e}$ is the electron diamagnetic frequency and $\eta_{e}$ = (dlnT$_{e}$/dr) / (dlnN/dr). Three (in)stability regions must be considered, viz. (c$_{i}$/R$\omega_{o})^{2}$ < 0.12 where cylindrical effects dominate and the plasma is stable ; 0.12 < (c$_{i}(R \omega_{o})^{2}$ 2 < 0.26 q$^{2}$ where the magnetic drift destabilizes the mode ; and 0.26 q$^{2}$ < (c$_{i}/R\omega_{o})^{2}$ where the plasma is stable again. (The numerical values are given for $\eta_{e}$e = $\eta_{i}$ = 2 and T$_{e}$ = T$_{i}$). Parallel electron heat conduction is stabilizing but ion viscosity broadens the instability domain. Under certain conditions, an important top-bottom asymmetry of the density fluctuation spectrum may arise.

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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